1. The Field of the Invention
This invention relates to systems and methods for transferring digital data within computer systems. More particularly, the present invention pertains to a high speed communication path that allows one or more remote computers to share the resources of a high speed host computer, thereby increasing the speed of operation of the remote computers.
2. The Background Art
Modern digital computers have become essential to business, science, industry, and military operations throughout the industrial world. In particular, the widespread availability of microcomputers, also often referred to as "personal computers", has made digital computers accessible to more people than ever before.
The affordability and widespread use of the microcomputer has caused a myriad of different microcomputer application programs to become available directed to those tasks that the microcomputer is best adapted. Many such applications, however, require the additional power of a mini or mainframe computer system unavailable in a microcomputer. Thus, many facilities are equipped with both a powerful mainframe or minicomputer, as well as a plurality of remote microcomputers located on the site.
Disadvantageously, the operating systems, architectures, and standards that have been developed for the microcomputer have differed from those developed for larger computer systems In view of the desire to retain efficient operations, these differences have made the interfacing of the different types of computers quite difficult.
Moreover, the internal and peripheral devices used with larger computers are often faster than the corresponding devices associated with each of the microcomputers. For example, while it is not generally economical to provide each microcomputer with a high capacity, fast-access magnetic hard disk drive memory device, it is effective to provide such a magnetic hard disk drive in connection with a mini or mainframe computer. Also, it is common for a high speed, high quality printer to be associated with a mini or mainframe computer, while not with a microcomputer.
Large computer systems often have excess space on their disk drive memory. Also, the printers associated with larger computers often sit idle much of the time. For these reasons, and because it is generally desirable to allow remote microcomputers to communicate with larger host computers, there has been a yet unfulfilled need for an effective communication link between a plurality of remote microcomputers and a larger host computer, whereby the remote computers could utilize directly the resources of the host computer.
Unfortunately, previously available computer systems do not provide for communication between a remote and a host computer in a manner that permits the remote computer to efficiently use the resources of the host computer. For example, data transmission systems such as local area networks and terminal communication systems, utilize serial data communication techniques that transmit data bits between computers one at a time over cables. This severely limits the speed of communication making impractical the transmission of data on a "clock cycle" basis, which is necessary for memory accesses by a microprocessor. The arbitration and managing functions exercised by local area networks slow communications even further. Thus, it has long been a need in the art that a remote computer and a host computer be able to communicate fast enough to share resources efficiently.
In view of the foregoing, it would be advantageous to develop a system and method for allowing a remote computer to share the resources of a host computer by providing high speed communication between the two. It would be a further advance if such a system were to allow a remote computer to access the disk drive of a host computer as a virtual disk drive. It would further benefit the users of smaller computers to provide a communication system for allowing a plurality of remote computers to off-load printing tasks to a host computer and to allow a remote computer to organize files into virtual disk partitions in a host computer disk drive. A data communication system for allowing one or more networks of remote computers to share the resources of a host computer, such as sharing of printers and file transfer functions, would be even a further step forward.